It all depends on your drive and SATA chipset.
If you have a compatible SATA chipset then you're in luck.
Then you can power your drive with your 360 (although I advice against it since it puts a NO_DVD flag in your NAND)
Otherwise you'll need a X360 USB and CK3i
Then you can begin extracting your DVD Keys with Jungleflasher.
This is pretty straight forward.
The actual flashing is more tricky.
It depends on your drive really.
You can have a Sputnik 360 installed or having a Kamikaze hack preformed.
Eitherway you'll have to unlock your drive in order to gain write access to it.
Everything should be explained more detailed in the manual that comes with Jungleflasher.
Link for the SATA chipsets that work:
here
However I reccommend a X360 USB.
It's far more simpler then SATA chipsets.
Besides you can get it off off ebay for cheap.